I started with two layers of polish on each nail, and then used a nail art brush to paint on some blobs based on pictures of lava lamps. I got one for Christmas when I was about nine, and it still works! Admittedly I rarely use it but I do rather like it. One dry I painted another coat of sheer polish over each nail. This blended the colours a bit which I think is where it went wrong, the colours bright jelly like look is great for lava lamps, but I think the 'lava' needed to be in a more contrasting colour.
Finally, I used silver polish at the top and bottom of each nail to give them a rocket lava lamp look. One other thing to mention about these 'lolly gloss' polishes is that they are scented! I certainly wouldn't choose a nail polish just because it's scented but it's a fun novelty. Initially the smell was quite sickly sweet, but once the nail polish element of the smell faded away about it was quite good, I think it smelt like fruit squash.